Abstract: A compact portable apparatus and method for heating gases for periods ranging from about one tenths of a second to several minutes to temperatures as high as 2700.degree. Celsius in 4 hrs. Graphite or metal oxide spherical pebbles which are placed in an externally thermally insulated cylindrical bed. The pebbles enclose and are heated by electrical resistive elements from which they are physically isolated. High heat storage density is achieved by designing the bed for high pressure loss operation and gas flow is in the downward direction. The bed is pressurized prior to initiating the gas flow with a quick acting valve or burst disc placed at the heater outlet. Typical applications are as a heat source for magnetohydrodynamic channels or wind tunnels. For magnetohydrodynamic applications a pulsed liquid seed metal injection method producing micrometer diameter liquid particles is disclosed.

Abstract: Apparatus and method for non-equilibrium MHD generation including a cyclone combustor, in which particulate metal is oxidized to form non-gaseous by-products. A low molecular weight working gas, such as hydrogen or helium, is energized by mixture thereof in said cyclone generator. Substantially non-gaseous oxidation by-products are removed by cyclonic action from the working fluid. The thus energized working fluid, with its swirling movement neutralized by the introduction of a further portion of working fluid, is then delivered through a nozzle to the MHD generator.

Abstract: Coal combustion and the capture of pollutants are optimized by a method which applies two mechanisms for sulphur capture, one in which pulverized coal particles suspended in the gas stream in the injection zone of the combustor are affected by reaction with a suspended sorbent, and another in which the particles are reentrained in the gas stream by a "sand storm" effect near the wall of the combustor. Use of the two mechanisms results, in commercial scale cyclone combustors, in 70 to 90% sulphur capture at economical Ca/S ratios. The method also minimizes emission of ash by removal from the pulverized coal fuel particles too small to be retained in the combustor and too large to be completely burned in the combustor, minimizes reevolution of sulphur compounds from slag by rapid and continuous removal of slag from the combustor, minimizes emission of NO.sub.x pollutants by maintaining a favorable overall fuel-rich stoichiometry.

Abstract: An air-cooled cyclone coal combustor comprises a horizontally disposed shell, provided with a non-sacrificial refractory liner. The liner is surrounded by an array of air-cooling tubes, the tubes serving both to cool the liner and to physically support and reinforce it. Air cooling in the manner disclosed facilities precise control of the thickness and flow of slag on internal walls of the combustor, so as to avoid reevolution from the slag of the sulfur pollutants. Pulverized coal fuel and a pulverized sulfur sorbent (limestone or the like), as well as primary and secondary combustion air, are introduced into the chamber at an end wall. The cooling air, heated regeneratively in the cooling tubes, provides the secondary air, and is introduced in the chamber in helical flow, at a radius outwardly from the radius at which the solids and primary combustion air are introduced into the chamber. A thermally insulated nozzle provides an outlet for combustion gases.